Almost 2,300 litres of spirits have been seized by customs officers targeting illegal sales.
Officials visited 77 shops in central Scotland, from Inverclyde to Midlothian, checking the details of alcohol on sale.
The eight-day HM Revenue and Customs (HMRC) operation aims to hit producers, storage facilities, wholesalers and retailers.
It has resulted in 2,281 litres of alcohol seized so far.
Chris Brett, HMRC’s alcohol taskforce manager in Scotland, said: “We are tackling excise fraud at all points of the supply chain, from production and storage through to sale. Anyone engaged in handling or selling smuggled alcohol should be aware that HMRC teams are active across Scotland.
“We are committed to stopping this criminal activity which costs the taxpayer around £1.2 billion in unpaid revenue each year.”
The customs officers visit traders to examine their records and carry out other investigations.
Chief Inspector Julie MacConnell, Renfrewshire area commander for Police Scotland, said: “We are determined to disrupt this type of activity, especially as it can fund organised crime.”